1. Field of the Invention
The invention is based on a turbine blade of a basic titanium alloy in which at least the region of the blade tip at the blade leading edge has a surface of a material which is more resistant to erosion than the basic titanium alloy. Such blades are preferentially used in the low pressure stages of steam turbines because, despite their size, they meet the mechanical strength requirements arising in this area at temperatures of around 100.degree. C. and do not excessively increase the rotor stresses. In this temperature range, the steam entering the turbine condenses and water droplets hit at high velocity against the turbine blade surfaces exposed to the entering steam. These surfaces are, in particular, the blade leading edges and the parts of the blade surface following on from the blade leading edges on the suction side. The water droplets can cause erosion damage. The blade regions located near the blade tips are particularly affected by this because the peripheral velocity of the blades is greatest at this point.
2. Discussion of Background
A turbine blade of the type mentioned at the beginning is known, for example, from GB-A-1479855 or EP-B1-0249092. The known turbine blade has, in the region of the blade tip, a blade region which includes the blade leading edge and was manufactured by brazing, by means of a silver braze or copper braze, a protective body containing titanium carbide onto a basic titanium alloy turbine blade without a protective body. Such a protective body is intended particularly to protect endangered regions of the turbine blade from erosion damage. The manufacture and application of the protective body to the turbine blade without a protective body are relatively complicated. In this arrangement, furthermore, difficulties with respect to the adhesion of the protective body on the basic titanium alloy of the titanium blade without protective body cannot be excluded.